Subsequent to rapid development of compound semiconductor industry, techniques for fabricating ICs and photoelectric elements are also moving forward to a new milestone, in which the high-speed microwave functional elements are always the focused issues. In the booming fields of sophisticated science such as radio data transmission, personal mobile and satellite communication, etc., the compound semiconductor element is playing pivotal key roles.
Materials in lattice-matched to Indium Phosphide (InP) have collected constant attention from the public due to their inherent photoelectric characters, wherein a resonant-tunneling diode (RTD) or a resonant-tunneling transistor (RTT) formed by GaInAs/AlInAs features a negative-differential-resistance with very high operable frequency. Therefore, the RTD or RTT is widely applied in microwave and milli-microwave devices as for analog-to-digital converter parity bit generator frequency multiplier and multiple-valued logic circuit, etc. However, the above mentioned phenomenon of negative-differential-resistance is affected by thermal effect, hence, the element can be applied only under low temperature condition to show off its outstanding features. This disadvantage seriously degrades the practicability of the RTD or RTT element.
Accordingly, the above-described customary element is in need of improvements.